Chips are used in a variety of electronic devices to perform one or more functions within such devices. For instance, a microprocessor chip may perform some or all of the central processing unit functions in a mobile phone. These chips are typically housed within packages that protect the chip from damage. Packages may be composed of any suitable insulating material, such as an epoxy mold. A lead frame mechanically supports the chip and includes leads or electrical terminals that are exposed to the external surfaces of the package, thus providing multiple electrical pathways between the package and another electronic device to which the package leads or terminals are coupled.
Part of this lead frame is a die flag on which the die is mounted within the package. Because the die is mounted on the die flag, the size of the die flag dictates the size of the die—that is, the area of the die flag surface to which the die is mounted dictates the area of the die surface mounted to the die flag. The die area should be the same size as, or smaller than, the die flag area. If the die area is larger than the die flag area, the die will extend over one or more edges of the die flag. This overextension makes the die and associated connections (e.g., wire bonds that electrically couple the die to leads or terminals) susceptible to mechanical stress and damage.